The present invention relates to the field of article feed mechanisms and sorters, and particularly to vibratory parts feeders having an attached vibratory feeder bowl.
Vibratory feeder bowls arid parts separators typically urge parts upwardly along a spiral path, by vibrating the spiral path both axially along and rotationally about its central axis. A vibratory drive unit is required to impart the necessary vibratory feed motion to the feeder bowl.
In the design of a vibratory parts feeder it has become an industry practice to attach the feeder bowl to a top member of the drive unit, wherein the top member and a stationary base member of the drive unit are connected by a plurality of drive springs. The attachment of the feeder bowl to the top member of the drive unit, and the attachment of the drive springs relative to the feeder bowl has been the subject of prior U.S. patents. For example, U.S. Pat. No. 4,181,216 to Cipu, U.S. Pat. No. 3,447,660 to Winaris, and U.S. Pat. No. 3,658,172 to Hacker disclose two methods of attaching the feeder bowl to the drive unit, and the mounting of the drive springs relative to the feeder bowl.
Designers of vibratory parts feeders have used several approaches to attach a feeder bowl to a drive unit. One approach, shown in FIG. 1, of attaching the feeder bowl (a) to the drive unit utilizes clamp nuts (b) that clamp a lower flange (e) of the cylindrical wall (c) of the feeder bowl (a) to the top member (d) of the drive unit. Another method, shown in FIG. 2, incorporates a plate welded (f) to the lower side of the bottom of the feeder bowl (h). The feeder bowl is secured to the top member (j) with bolts (i) that thread vertically into the plate. A third alternative, shown in FIG. 3, attaches the feeder bowl (k) to the drive unit with bolts (l), that pass horizontally through clearance holes in the lower flange (h) of the cylindrical wall (m) of the feeder bowl (k) and engage the outer periphery of the top member (o).
These three approaches to attach the feeder bowl to the drive unit have a common limitation. Specifically, these prior methods of attachment allow the sidewall and bottom of the feeder bowl to flex, thereby wasting a portion of the feed motion intended for transfer to the articles in the feeder bowl.
The relative mechanical advantage of the drive unit is dependent upon the location where the drive springs attach to the top member. The industry standard is to mount the drive springs to the top member inboard of the cylindrical wall of the feeder bowl. One device, shown in U.S. Pat. No. 4,181,216 to Cipu, includes mounting the drive springs to the top member outboard of the cylindrical wall of the feeder bowl. However, Cipu attaches the feeder bowl centrally to the top member so flexing is still a problem.
The combined method of attaching the feeder bowl to the top member of the drive unit, and time mounting of the drive springs to the top member relative to the feeder bowl impact the quantity of vibratory feed motion imparted to the articles in the feeder bowl.
There remains a need for an improved vibratory parts feeder that maximizes the mechanical advantage of the drive unit and minimizes the amount of vibratory feed motion washed by the flexing of the cylindrical wall and the bottom of the feeder bowl.